The main differences between red and white wines are:

1. According to the different colors of grapes, grape varieties can be divided into three major categories: white varieties (white skin and white flesh), red varieties (red skin and white flesh) and dyed varieties (red skin and red flesh). White varieties are used to make white wine, dyed varieties can only make red wine, while red varieties can make a variety of wines ranging from white to deep red color.

2. White wine is fermented from white grape juice, and red wine is fermented from grape juice (liquid part) mixed with grape pomace (solid part), and the depth of its color is determined by the strength of the liquid part of the impregnation of the solid part of the impregnation, the stronger the impregnation, the deeper the color.

3. The solid part of the wine is not only the pigment, but also the tannin, which is a phenolic substance like the pigment, and the darker the color of the wine, the higher the content of the phenolic substance composed of pigment and tannin.

Therefore, the main difference between red and white wines is the difference in the content and type of phenolic substances between them.